November 22, 2006

Stress, Dopamine and Unusual Experiences in Everyday Life

An interesting entry at the British Psychological Society Blog discusses the different perspectives on unusual experiences, perceptions, and dopamine. The entry notes:

"To generalise, most psychiatrists see themselves as applied neuroscientists, while most clinical psychologists explain psychopathology in terms of mental processes and social relationships, and make little reference to the brain. This rift is partly fuelled by a lack of research that examines how biological and psychological factors interact to cause mental ill health. One 2005 study was a notable and refreshing exception, and has provided a compelling glimpse into how stress and the dopamine system interact to predict the presence of unusual experiences in everyday life."

In the study, it was found that "for the relatives [of people who have psychosis/ schizophrenia], those with the most reactive dopamine systems had unusual experiences (such as hearing voices or feeling unreal) in response to everyday stresses." Additionally, the study found, "Stress wasn’t linked to unusual experiences in any of the other participants. In other words, the presence of psychotic experiences could only be accounted for by examining a combination of genetic risk, dopamine reactivity and stress in everyday life."

This study is important because one of the biggest debates in science today is whether psychiatric disorders are mainly a result of lifelong brain dysfunction, or the result of stress and trauma on a brain. As this study suggests - increasingly the research is showing that its not one or the other - but rather that a biological or genetic predisposition (due to genes and/or prenatal or early childhood stresses) increase a person's predisposition towards thought and mood disorders. In other words - biology influences brain development (including the risk for mood and thought disorders), and stresses and trauma also impact development of the brain, and even gene expression. Increasingly, it seems, both biology (as a fundamental risk factor) and environment (as a contributing risk factor or triggering factor) are important in the develpment of mental illnesses.

While it has been known for a long time that only in approximately 50% of the cases when one identical twin gets schizophrenia does the second twin get schizophrenia (making a clear case that schizophrenia is not a purely genetic disorder) -- researchers are only now starting to get some good data on why this is the case, and how environmental factors might be playing a contributing or triggering role.

For families that have any history of mental illness this is hopeful news because research suggests that many instances of psychiatric disorders might be avoided in the future if families learn to identify and make efforts to moderate the stresses that children are exposed to (including family and social stresses).